failure

get:by looks a key up in a map. it produces a unit: ~ when the key is missing, [~ value] when it is there.

look up ann's age.

=> |% ++ ages (my ~[['ted' 42] ['ann' 30]]) --
glossary

=> sets the subject to its head, then evaluates its tail against it.

=>([a=1 b=2] b) is 2.

|% makes a core: a battery of named arms, each written ++ name.

reach an arm back out with =< or arm:core.

=<  a
|%
++  a  5
--

is 5.

%: calls a gate with several arguments, gathering them into one sample.

%:(add 2 3) is 5.

irregular forms:

(gate a b c) is %:(gate a b c)

my builds a map from a list of key-value pairs, like malt.

:~ makes a null-terminated list.

:~(1 2 3) is ~[1 2 3].

irregular forms:

~[a b c] is :~(a b c)

:* makes a tuple of many elements, nesting to the right.

:*(1 2 3) is [1 2 3].

irregular forms:

[a b c d] is :*(a b c d)

%= resolves a wing with some faces changed.

=/(a [x=1 y=2] a(x 9)) is [x=9 y=2].

irregular forms:

a(x 9) is %=(a x 9)

$(a b) restarts a loop with a changed to b